This project focuses mainly on harmonising mix design of cold-recycled bitumen stabilised materials following the existing scientific and engineering experience and approaches. The key objective is to develop and recommend comprehensive mix design and characterisation by studying compaction methods, curing procedures and performance tests. The output should be applicable to all variants of cold-recycled mixtures containing bituminous binders or combination with other binders or alternative fines. Aspects considerable for defining durability of cold-recycled mixtures will be evaluated and specified as well.

Existing practice focuses only on water immersion and stiffness. Both characteristics are not a standard part in all mix designs known in Europe. Nevertheless to vindicate and promote cold recycling as an equivalent solution for hot mix asphalt the durability must be predictable. For this reason the project focuses on assessing stiffness, fatigue behaviour, resistance to cracking and on long-term moisture effects. Different test procedures will be evaluated and most suitable approach recommended including proposed threshold limits. This will make performance-based mix design possible. Further gained results will be used for formulating preferable inclusion of cold-recycled mixture in existing pavement design manuals. It is primarily not expected to modify the mechanistic calculation of pavement design, more important seems to be the definition of typical structures where cold-recycled bitumen stabilised materials are used for base or binder courses and critical parameters are defined. This should allow to road administrators and designer to use cold-recycled mixtures as a standard component of a pavement structure.

Multiple recycling should present one of the key advantages of cold recycling techniques. The activation of reclaimed asphalt, impact of material ageing and range of applicability (for cold recycled mixtures and for the partial substitute of aggregates in hot mix asphalts) will be specified and the most suitable practice recommended. The final part of the project focuses on environmental stability/compatibility which becomes an integral part of building materials' use and modern civil engineering. Leaching of cold-recycled mixtures will be specified with recommendations for threshold limits. At the same time some hazardous or problematic materials in existing pavements will be assessed in relation to their immobilisation and most suitable reuse by cold recycling (tar, asbestos, crumb-rubber modified asphalt). Part of this environmental assessment will be devoted to technically correct assessment of cold-recycled mixtures with respect to their carbon footprint. It is believed, that in the near future, such energy equivalent will be considered in decision about most appropriate technical solutions in pavement construction or rehabilitation and energy savings achievable by recycling should be considered as a benefit.

The project bundles the capabilities of science, public interests and industrial knowledge to overcome the described problem and to offer an appropriate solution.